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(No Model.) 2 Sheets-Sheet 1.

' H. STEVEN.

ENGINE.

N0. 604,643. Patented May 24, 1898.

i W/TIVESSES m%/ (No Model.) 2 Sheets-Sheet 2.

H; STEVEN. ENGINE.

N0. 604,643 Patented May 24, 1898 aUIIII/IIIIIII/II/IIIIIIIII VENTOH By A7701? Wzy/ g 1/, N

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HENRI STEVEN, OF SAN SEBASTIAN, SPAIN.

ENGINE.

SPECIFICATION forming part of Letters Patent No. 604,643, dated May 24:, 1898.

Application filed April 11, 1898. Serial No. 677,204. (No model.)

T0 at whom it may concern:

Be it known that I, HENRI STEVEN, a subject of the King of Belgium, and a resident of San Sebastian, Spain, have invented certain new and useful Improvements in Engines, of which the followingis a full, clear, and exact specification.

My invention relates to engines in which the gaseous motive agent works by expansion, and has for its object to prevent the condensation of the motive agent during the expansion period.

The invention is applicable particularly to steam-engines.

In my United States Patent No. 601,531, dated March 29, 1898, I have described an invention according to which a heating fluid of higher temperature than the main supply of working steam is introduced into said steam in gradually-increasing quantity as the expansion of the steam progresses. Said heating fluid, as described in my said patent, preferably consists of superheated steam.

Practical trials have shown that good results are obtained only when the heating fluid (superheated steam) has a temperature considerably in excess of that of the main work ing supply of steam. Thus in the common type of steam-engine, in which the working chamber is a cylinder and the movable resistance is a reciprocating piston, I have secured the best results by alternately admitting to the ends of the cylinder a small quantity of a heating fluid, such as superheated steam, of a very high temperature and providing for an expansion of the superheated steam or fluid in the superheater. The distributing device for thesaid heating fluid must be of a special construction in view of the very high temperature employed, at which slide-valves, cocks, and the like would soon be destroyed, as it would be impossible to effectuallylubricate them. This will be understood upon considering that I may employ such high temperatures as to cause the pipes conveying the heating fluid to the cylinder to become red-hot.

In my above-mentioned patent the distributing-valve for the heating fluid is an automatic valve sliding between two seats and alternately establishing a communication from the superheater to the opposite ends of the cylinder.

'Fig. 1.

In my present invention I employ separate superheaters for each cylinder end. Further, the distributing-valve oscillates instead of reciprocatingbetween two seats; also, the heating fluid is discharged into the cylinder longitudinallythat is, in the direction in which the resistance or piston is arranged to move. These features of my invention and others that are employed to secure a proper temperature and condition of the working agent and of the heating fluid will now be described in detail and then specifically defined in the appended claims.

Reference is to be had to the accompanying drawings, forming a part of this specification, in which similar characters of reference indicate corresponding parts in all the figures.

Figure 1 is an elevation of a steam-engine provided with my superheating arrangement, the latter appearing in section. Fig. 2 is a sectional plan thereof, taken on line 2 2 of Figs. 3 and a are two sections of the distributing-valve,taken at right angles to each other; and Figs. 5 and 6 are two sections at right angles to each otherof asuperheating-coil constructed according to my invention.

Steam from the boiler passes into the pipe Z, and thence downward into a series of pipes U,extending into the superl1eater,which comprises an outer metallic shell S, lined interiorly with refractory brickwork L. F is the grate, and E the furnace proper. Each pipe U is looped or U-shaped, the inlet ends or descending members connecting with the chamber Z, which communicates directly with the pipe Z, while the outlet ends or rising members of the pipes U lead to a box or chamber X, which is separated from the chamber Z by a zigzag partition G. The pipes U constitute a heater for the purpose of converting into steam any particles of water that may be suspended in the live steam, so that dry steam is obtained. This dry steam passes into the box X, and then the main portion of the steam proceeds by way of the pipe Y to the cylinder IV, having a slide-valve V and an expansion-valve T, which may be of any approved construction. A

portion of the dry steam is conveyed by way of the pipe A to a cock or valve B, which when open admits the dry steam into two ICO pipes coiled within the superheater to form superheating-coils D. The coils are embedded in metal cast about them. This is done for the purpose of preventing the oxidation which would take place if the pipes were exposed directly to the furnace-gases, and also for providing a body of greater heat-retaining capacity, so as to avoid sudden changes in the heating effectfor instance, when the grate is being cleaned.

From the superheating-coils D two pipes G lead to the passages R R in the casing II of the distributing-valve Q. This valve is pivoted at Q to oscillate between the two seats P P at the inner ends of the pipes I I, which lead to the cylinder W to discharge the heating fluid longitudinally of the cylinder through the nozzles or ports J J (see Fig. 2) against the piston O.

The'operation of the engine is as follows: The live steam dried in the heater U is admitted and cut off by the operation of the slidevalve V and expansion-valve or cut-oft valve Tin substantially the usual manner. Supposing the live steam to beworking in that portion of the cylinder in which the nozzle or port J is located, said steam will pass into the pipe I and exert a pressure on the valve Q. The other face of said valve is practically free from pressure, since steam is exhausted from the other end of the cylinder. Thus the valve Q will be thrown over from the seat P against the seat' P almost at the same time that the slide-valve V admits steam to the cylinder.

superheated steam from the inner coil D will then pass through pipe G, passage R, pipe I, and nozzle J into the cylinder to mix with the working steam therein in a quantity correspondin g to the pressure of said steam. When the admission of live steam is discontinued by the operation of the cut-off valve T, (see Fig. 2,) the steam in the cylinder will continue to work by expansion, so that its pressure will diminish gradually, and this decrease of pressure creates, as it were, a suction which causes progressively larger quantities of superheated steam to enter the cylinder during the expansion period. The greater cooling effect due to continued expansion is thus automatically compensated for by the corresponding increase in the admission of the heating medium. At the end of the stroke the position of the slide-valve V is reversed, and the valve Q is brought back to the position shown in Fig. 8, causing the superheated steam from the outer coil D to pass to the cylinder through pipe G, passage R, pipe I, and nozzle J. superheated steam being discharged in the same direction in which the piston O is moving the impact of said steam is utilized; also the superheated steam will better fill the working chamber and mix more effectually with the expanding steam.

The superheating-coils D, such as shown in Figs. 1 and 2, are preferably employed for small engines only. For engines of a large size I prefer the arrangement shown in Figs.

. 5 and 6, in which there are spaced vertical series of sinuous pipes D, embedded in metal N, cast about them, for the same purpose as hereinbefore referred to.

It will be understood that the valve Q has a double function, since it not only closes the orifices of the pipes I I at the seats P P, but the ports at the inner ends of the channels R R. By this arrangement one of the superheating-coils D or D is cut off from communication with the cylinder, while the other coil supplies superheated steam to the said cylinder, and thus the coil, which for the time being is inactive, gets filled with a new supply of superheated steam. The proportion of superheated steam to live steam may be readily varied by an appropriate adjustment of the valve B, which is practically a throttlevalve.

I desire it to be understood that various modifications may be made without departing from the nature of my invention. Thus the superheater, instead of being a separate structure, as shown, may form a part of the boiler-furnace.

Having thus described my invention, I claim as new and desire to secure by Letters Patent 1. The combination with the movable resistance or piston, the cylinder or working chamber, and means for supplying a main motive agent alternately to both ends of the cylinder, of a separate superheater for each end of the cylinder, connections from the superheaters to the cylinder, and a shifting valve for alternately admitting the heating medium from the superheaters to the cylinder.

2. The combination, with movable resistance or piston, the cylinder or working chamber, means for supplying a motive agent to said cy1inder,ports or nozzles arranged longitudinally to discharge a fluid in the same direction in which the piston moves, and a superheating arrangement connected with said ports.

3. The combination with the piston or movable resistance, the cylinder or working chamber, and means for supplying a motive agent thereto, of two superheaters, a valve-casing having two passages connected to the ends of the cylinder, and two passages connected to said superheaters, and a shifting valve which in each of its positions closes one of the cylinder-passages and one of the superheaterpassages.

4. The combination with the piston or movable resistance, the cylinder or working chamber, and means for supplying a motive agent thereto, of two superheaters, a valve-casing having two passages connected to the ends of the cylinder, and two passages connected to said superheaters, and an oscillating valve which in each of its positions closes one of heater-passages.

5. The combination with the piston or movable resistance, the cylinder or Working chamher, and means for supplying a motive agent thereto, of avalve-casinghavingtwo passages connected to the ends of the cylinder, a superhcating arrangement connected to the valve-casing, and an oscillating valve for alternately admitting the superheated medium to the opposite ends of the cylinder.

6. The combination with the piston or me vable resistance, the cylinder or Working chamber, a furnace, a supply-pipe for the motive agent, a series of pipes connected to said supply-pipe and extending into said furnace to dry the motive agent, a device for distributing the motive agent in the cylinder, a pipe leading from the discharge end of the said series of pipes to the distributing device, a superheating arrangement located in said furnace and having connections to each end of the cylinder, and an oscillating valve for alternately admitting the superheated medium to opposite ends of the cylinder.

7. The combination with the piston or movable resistance, the cylinder or Working chamher, a device for distributing the motive agent in the cylinder, and a supply-pipe leading to said device, of a branch pipe connected to said su pply-pipe, a superheating arrangement connected to said branch pipe, a throttlevalve controlling the connection of the superheating arrangement With the supply-pipe, connections from the superheating arrangement to each end of the cylinder, and a shifting valve for alternately admitting the superheated medium to opposite ends of the cylinder.

HENRI STEVEN.

Witnesses:

CARLOS GLEN, FRAN. Bnneononna. 

